Some conventional networks employ redundant devices to load balance or to reduce the likelihood that devices inside the network may be cut off from devices outside the network. Conventionally, one of the redundant devices may be configured as a primary router and one or more other redundant devices may be configured to be a backup router(s). Thus, the primary router may send routing information such as network address translation (NAT) data to the backup router(s). One conventional system for mirroring NAT data between two redundant devices is known as stateful NAT (SNAT). In the event that the primary router goes down, a backup router may then perform failover services for the primary router by, for example, managing NAT data and taking over routing existing traffic streams between devices inside the network and devices outside the network.
When the primary router becomes active once again, NAT entries may be out of date and/or not properly established in the primary router's NAT database at the time the primary router comes back up. Thus, the primary router may establish a connection with the backup router currently handling network traffic to synchronize NAT data. However, when the primary router becomes active, the primary router may also begin advertising its existence and its routing information to neighboring devices causing traffic to begin to route through the primary device before NAT synchronization has completed. This may break stream based sessions that store sequence information and/or acknowledgment information in NAT data. Some conventional systems attempt to prevent this by configuring the primary router with a static delay before the primary router begins to advertise itself as a path between devices inside the network and devices outside the network. However, when there is a large amount of NAT data to transfer between the backup router and the primary router, the data transfer may not have completed when the static delay has ended. Additionally, during this delay the primary router may not be able to perform other tasks for which the primary router is responsible because neighboring devices may not recognize that the primary router is active.